1. Field of the Invention
The present invention in general relates to fluid detection systems that include a central controller and a plurality of probes remote from the controller for detecting the fluid status at the probe locations, and more particularly to such a system that is programmable.
2. Description of the Prior Art
Fluid detection systems that include a central controller and numerous probes that are controlled by the controller and report on the fluid status at remote probe locations are well known. Typically such systems are used to detect leaks in underground hydrocarbon tanks. U.S. Pat. No. 4,740,777 on an invention of Laurence S. Slocum and Sara M. Mussmann describes a programmable fluid detector in which the operator can select alarm conditions individually for each probe from many possible alarm conditions including probe failure, hydrocarbon present, water present, and the dry condition. The operator can also select relay latching conditions. In the above system when an alarm occurs the associated relay remains latched until the system is turned off, the cause of the alarm is removed, and the system is restarted. It is also known in the art to permit a responsible person to acknowledge an alarm by entering a secret code which allows the alarm to be reset, which deactivates the alarm. In the above systems and all of the prior fluid detectors in the field, the procedure by which an alarm may be deactivated or a relay released is fixed.